Hayward fault threat upgraded

Some scientists say the Hayward fault, long the focus of geologists as the most likely candidate for the San Francisco Bay area’s next big earthquake, might be even more dangerous than thought.

Geologists analyzed gradual changes in stress on the deepest parts of faults in the area. They found that several faults, including the southern portion of the Hayward fault, might be more prepared to rupture than previously estimated.

The research suggests current earthquake forecasts for the area also might underestimate the danger on two other faults: the Rodgers Creek fault that runs from San Pablo Bay north past Santa Rosa and the northern portion of the Calaveras fault from Sunol to the Danville area.